Download WSMO Studio 0.8.0 (14-Sep-2009, Release information) for:
Individual plug-ins can be downloaded at http://sourceforge.net/project/showfiles.php?group_id=119791
An Eclipse update site that can be used directly from Eclipse (Help --> Software Updates --> Find and Install) is available at http://www.wsmostudio.org/updates/. See also the FAQ entry on using the update site.
Previous WSMO Studio releases are available here